Search found 63 matches

by davidryan3f
Sun Mar 17, 2019 12:45 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: galvanic/voltaic cells
Replies: 3
Views: 165

Re: galvanic/voltaic cells

those terms are synonymous I believe.
by davidryan3f
Sun Mar 17, 2019 12:44 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Rate Determining Step
Replies: 9
Views: 281

Re: Rate Determining Step

The slow step can't have intermediates. You substitute them using values in the other steps.
by davidryan3f
Sun Mar 17, 2019 12:43 am
Forum: Balancing Redox Reactions
Topic: balaning redox reactions
Replies: 3
Views: 224

Re: balaning redox reactions

yes for example, if the ion has a +2 charge and the coefficient in from of it is 2, then the charge for that species would be +4.
by davidryan3f
Sun Mar 17, 2019 12:42 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: first law
Replies: 2
Views: 175

Re: first law

the first law also states that heat energy cannot be created or destroyed
by davidryan3f
Sun Mar 17, 2019 12:41 am
Forum: Ideal Gases
Topic: ICE table
Replies: 3
Views: 218

Re: ICE table

You solve for Ka by setting up the equation for the equilibrium constant and pugging in the given values at equilibrium or substitute these values using X or a variation of that. Then you use algebra to solve for Ka.
by davidryan3f
Sat Mar 16, 2019 3:29 pm
Forum: Balancing Redox Reactions
Topic: multiplying half reactions [ENDORSED]
Replies: 4
Views: 96

multiplying half reactions [ENDORSED]

If you multiply a half reaction by a certain number in order to make the two half reactions have the same number of electrons, do you multiply the cell potential for the half reaction by that same factor?
by davidryan3f
Fri Mar 15, 2019 11:05 pm
Forum: Calculating Work of Expansion
Topic: expansion work question
Replies: 1
Views: 196

expansion work question

If a question states that a reaction between two gasses takes place, but does not specify a volume or a change in volume, how do we know if expansion work is done?
by davidryan3f
Fri Mar 15, 2019 7:51 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: state functions?
Replies: 2
Views: 157

state functions?

Ould someone explain what exactly a state function is?
by davidryan3f
Fri Mar 15, 2019 7:50 pm
Forum: Phase Changes & Related Calculations
Topic: removing heat from system
Replies: 1
Views: 186

removing heat from system

If a reaction is exothermic, will the temperature always decrease? In not, what are the exceptions to this rule?
by davidryan3f
Fri Mar 15, 2019 7:46 pm
Forum: Phase Changes & Related Calculations
Topic: removing heat from system
Replies: 4
Views: 196

removing heat from system

If a reaction is exothermic, will the temperature always decrease? In not, what are the exceptions to this rule?
by davidryan3f
Fri Mar 15, 2019 6:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: addition of solid into a reaction
Replies: 1
Views: 42

addition of solid into a reaction

If the amount of a solid is added to a reaction that is already at equilibrium, will the reaction shift left or right, or will it remain at equilibrium since the item added was a solid?
by davidryan3f
Thu Mar 14, 2019 11:12 pm
Forum: Zero Order Reactions
Topic: Order distinction
Replies: 9
Views: 247

Re: Order distinction

the order of a reaction can be determined by looking at the rate law. Add up the exponents on each reactant and that gives you the order.
by davidryan3f
Thu Mar 14, 2019 11:04 pm
Forum: General Rate Laws
Topic: slow/fast steps
Replies: 7
Views: 93

slow/fast steps

will it be told to us which step is the slow step and which is the fast step???? asking for a friend
by davidryan3f
Thu Mar 14, 2019 11:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram and Ecell [ENDORSED]
Replies: 7
Views: 27296

Re: Cell Diagram and Ecell [ENDORSED]

jane_ni_2d wrote:how can you tell which is the anode and which is the cathode?

the anode is always on the right of the cell diagram and the cathode is on the right.
by davidryan3f
Thu Mar 14, 2019 9:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 8
Views: 146

Re: Anode and Cathode

In a cell diagram, the cathode was always on the right side of the double bar divider thing.
by davidryan3f
Thu Mar 14, 2019 9:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Effect of concentration on cell potential
Replies: 2
Views: 65

Re: Effect of concentration on cell potential

simply stated, if you increase the concentration of the reactant or decrease the concentration of product the cell potential will increase.
by davidryan3f
Thu Mar 14, 2019 9:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: cell diagram question
Replies: 1
Views: 36

cell diagram question

how do you know what is the cathode and what is the anode when looking at a cell diagram?
by davidryan3f
Sun Feb 10, 2019 10:28 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta H and Delta U
Replies: 1
Views: 39

Delta H and Delta U

What is the difference between Delta H and Delta U?
by davidryan3f
Mon Feb 04, 2019 4:54 pm
Forum: Phase Changes & Related Calculations
Topic: Heat and Condensation
Replies: 9
Views: 136

Re: Heat and Condensation

Condensation is exothermic, releases heat, because it is the changing of a gas state to a liquid state.
by davidryan3f
Mon Feb 04, 2019 4:52 pm
Forum: Phase Changes & Related Calculations
Topic: Negative work
Replies: 11
Views: 180

Re: Negative work

Yes negative work will occur when the system does work on its surroundings rather than the surroundings doing work oil the system.
by davidryan3f
Mon Feb 04, 2019 4:50 pm
Forum: Phase Changes & Related Calculations
Topic: Type of systems
Replies: 12
Views: 253

Re: Type of systems

An isolated and closed system are different things. A closed system allows for the exchange of energy in and out of the system. However it does not allow matter to move in and out. On the other hand, an isolated system is completely closed off and does not allow the transfer or heat or energy.
by davidryan3f
Sun Jan 27, 2019 5:01 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy signs
Replies: 13
Views: 170

Re: Enthalpy signs

Delta H is positive when the reaction is endothermic and Delta H is negative when the reaction is exothermic.
by davidryan3f
Sun Jan 27, 2019 4:57 pm
Forum: Phase Changes & Related Calculations
Topic: Why are phase changes endothermic?
Replies: 11
Views: 162

Re: Why are phase changes endothermic?

Phase changes from solid-->liquid-->vapor are endothermic reactions because it requires an input of heat and energy to break the intermolecular forces.
by davidryan3f
Sun Jan 27, 2019 4:53 pm
Forum: Phase Changes & Related Calculations
Topic: Delta H
Replies: 11
Views: 194

Re: Delta H

H stands for enthalpy. So delta H represents the change in enthalpy during a reaction. If delta H is positive then the reaction requires energy and is endothermic. If delta H is negative then the reaction releases energy and is exothermic.
by davidryan3f
Wed Jan 16, 2019 5:03 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids
Replies: 6
Views: 94

Re: Acids

A weak acid or base does not dissociate fully while a strong acid or base does indeed dissociate fully ion the solution.
by davidryan3f
Wed Jan 16, 2019 5:01 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Solids and liquids in K
Replies: 6
Views: 136

Solids and liquids in K

I know that you don't include solids and liquids into the equation when calculating the equilibrium constant but could someone please explain to me why that is? Thanks friends
by davidryan3f
Wed Jan 16, 2019 4:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: % Ionization
Replies: 3
Views: 72

Re: % Ionization

To calculate the percent ionization, divide the conjugate acid or base equilibrium molarity by the acid or base initial molarity.
by davidryan3f
Sun Jan 13, 2019 5:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: True or False regarding reaction mixture [ENDORSED]
Replies: 10
Views: 143

Re: True or False regarding reaction mixture [ENDORSED]

yes that is basically the definition of equilibrium.
by davidryan3f
Sun Jan 13, 2019 5:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solids and liquids [ENDORSED]
Replies: 4
Views: 95

Re: solids and liquids [ENDORSED]

Molarity of a solid and liquid cannot change during the course of a reaction so there is no need to include them when finding K.
by davidryan3f
Sun Jan 13, 2019 5:36 pm
Forum: Ideal Gases
Topic: Pv=nRT [ENDORSED]
Replies: 12
Views: 206

Re: Pv=nRT [ENDORSED]

Henry Dudley 1G wrote:What is the value of R?

R= 0.08206 L atm/mol K. This is given to us on tests I believe.
by davidryan3f
Sun Dec 09, 2018 3:56 pm
Forum: Naming
Topic: Naming question with anion
Replies: 2
Views: 247

Re: Naming question with anion

anions in coordination compounds will have the endings -o -ido or -ato.
by davidryan3f
Sun Dec 09, 2018 3:56 pm
Forum: DeBroglie Equation
Topic: Calculating Velocity
Replies: 9
Views: 564

Re: Calculating Velocity

yes, the two equations involving velocity are p=mv and KE= 1/2mv^2
by davidryan3f
Sun Dec 09, 2018 3:55 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 6
Views: 267

Re: Hybrid Orbitals

the answer would be sp, sp2, sp3, sp3d etc
by davidryan3f
Sun Dec 09, 2018 3:53 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 3
Views: 238

Re: Cisplatin

Cisplatin has a central atom of platinum with two Cl attached and two NH3 attached. It is tetrahedral.
by davidryan3f
Sun Dec 09, 2018 3:52 pm
Forum: Bond Lengths & Energies
Topic: Shape of molecule
Replies: 4
Views: 255

Re: Shape of molecule

The greater the surface area off the molecule, the stronger the attraction/bond will be.
by davidryan3f
Sun Dec 09, 2018 3:51 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Size and Polarizability
Replies: 4
Views: 276

Re: Size and Polarizability

the size of the atom refers to the atomic radius. Atomic radius increases as you go down the periodic table and to the left on the periodic table.
by davidryan3f
Sun Dec 09, 2018 3:49 pm
Forum: Air Pollution & Acid Rain
Topic: Basic Rain
Replies: 5
Views: 242

Re: Basic Rain

I don't think it could physically happen in the conditions present on earth but it is certainly chemically possible.
by davidryan3f
Sun Dec 09, 2018 3:49 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: acid rain formula
Replies: 4
Views: 99

acid rain formula

what is the chemical equation for acid rain?? I think we went over this in class but I missed it in my notes.
by davidryan3f
Sun Dec 09, 2018 3:47 pm
Forum: Coordinate Covalent Bonds
Topic: polydentates
Replies: 5
Views: 270

Re: polydentates

Either simply memorize the common polydentates or draw the Lewis structure to determine if has two or more bonds that attach it to the central atom.
by davidryan3f
Sun Dec 09, 2018 10:50 am
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 18
Views: 608

Re: Trend of Electronegativity

Electronegativity increases as you go up the periodic table and as you go across the periodic table. Same goes for ionization energy.
by davidryan3f
Sun Dec 09, 2018 10:50 am
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 7
Views: 388

Re: Mass Percent Composition

If it does not add up to 100%, then the question is incorrect. The elements that are apart of the compound have to add up to 100% or else there is a missing element.
by davidryan3f
Sun Dec 09, 2018 10:47 am
Forum: DeBroglie Equation
Topic: Momentum
Replies: 10
Views: 500

Re: Momentum

You will not always be given the momentum. Solve the debroglie equation algebraically. The question will always give you enough variables to solve for the missing ones.
by davidryan3f
Sun Dec 09, 2018 10:45 am
Forum: Conjugate Acids & Bases
Topic: Conjugate Bases
Replies: 7
Views: 289

Re: Conjugate Bases

Conjugate bases are the result of the acid after it donates its proton. Comjugate acids are the result of the base after it accepts its proton.
by davidryan3f
Sun Dec 09, 2018 10:44 am
Forum: Biological Examples
Topic: Cisplatin
Replies: 2
Views: 212

Cisplatin

How does the fact that the ligands in cisplatin only bind at one site help account for the way that the drug stops cell division?
by davidryan3f
Sat Dec 08, 2018 11:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: Test #2 Question #5b
Replies: 2
Views: 189

Re: Test #2 Question #5b

nodal planes are the regions in which there is a zero % chance of finding an electron.
by davidryan3f
Sat Dec 08, 2018 11:16 pm
Forum: Properties of Light
Topic: Speed of Light
Replies: 41
Views: 763

Re: Speed of Light

light always travels at the same speed regardless of wavelength or amplitude. it is a constant.
by davidryan3f
Sat Dec 08, 2018 11:15 pm
Forum: Conjugate Acids & Bases
Topic: Acceptor and Donor?
Replies: 3
Views: 228

Re: Acceptor and Donor?

yes, the acid donates the proton and its conjugate receives the proton. the same goes for bases.
by davidryan3f
Sat Dec 08, 2018 11:14 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: HOCl vs HOI
Replies: 9
Views: 449

Re: HOCl vs HOI

Cl is considerably more electronegative than I, so the O-H bond is stronger than the O-I bond. therefore it is a stronger acid.
by davidryan3f
Sun Dec 02, 2018 11:48 pm
Forum: Sigma & Pi Bonds
Topic: Which bond would break first.
Replies: 15
Views: 543

Re: Which bond would break first.

the pi bond would break first because it is weaker than the sigma bond. It has a lower dissociation energy so it will break first.
by davidryan3f
Sun Dec 02, 2018 11:47 pm
Forum: Hybridization
Topic: tetrahedral
Replies: 5
Views: 112

tetrahedral

can someone explain to me why tetrahedral is sp3 hybridization?
by davidryan3f
Sun Dec 02, 2018 11:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs angular?
Replies: 15
Views: 244

Re: Bent vs angular?

Bent is just another name for angular. they are synonyms .
by davidryan3f
Sun Nov 25, 2018 4:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 7
Views: 140

Re: Molecular Shape

A molecule with a seesaw molecular geometry will have a total of 5 electron domains and one of them will be a lone pair of electrons. The molecule will have angles of 120, 180, and 90 degrees at various locations.
by davidryan3f
Sun Nov 25, 2018 4:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: electron arrangement and molecular geometry
Replies: 1
Views: 26

electron arrangement and molecular geometry

What I the difference between electron arrangement and molecular geometry? I get that molecular geometry is a more specific description of the atom but Im not sure the difference between the two terms.
by davidryan3f
Sun Nov 25, 2018 4:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: pi and sigma bonds
Replies: 9
Views: 174

Re: pi and sigma bonds

Sigma bonds have more energy because since they are stronger bonds, they require more energy to be broken than pi bonds. Therefore they have more energy themselves.
by davidryan3f
Sun Nov 04, 2018 3:22 pm
Forum: Photoelectric Effect
Topic: intensity
Replies: 4
Views: 116

intensity

how does increasing the intensity of the incoming photon affect the energy of the photon. Does it increase its energy, and if so, does that increase the number of electrons that will be emitted?
by davidryan3f
Sun Nov 04, 2018 3:19 pm
Forum: Quantum Numbers and The H-Atom
Topic: degeneracy in quantum numbers
Replies: 3
Views: 95

degeneracy in quantum numbers

Could someone explain what exactly degeneracy is in quantum numbers?
by davidryan3f
Sun Nov 04, 2018 3:18 pm
Forum: DeBroglie Equation
Topic: NUETRON DIFFRACTION [ENDORSED]
Replies: 1
Views: 243

NUETRON DIFFRACTION [ENDORSED]

Can someone explain why neutrons do not diffract?
by davidryan3f
Sun Oct 28, 2018 11:31 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 16
Views: 339

Covalent Bonds

This may be a dumb question but im a little confused. Can non metals form cations. if not, why can't they?
by davidryan3f
Sun Oct 28, 2018 11:29 pm
Forum: Ionic & Covalent Bonds
Topic: Changes in Form
Replies: 2
Views: 71

Re: Changes in Form

No, I do not believe that the state of the molecule effects the type of bond that will form.
by davidryan3f
Sun Oct 28, 2018 11:26 pm
Forum: Ionic & Covalent Bonds
Topic: the Octet rule
Replies: 21
Views: 418

Re: the Octet rule

yes, there are a few exceptions. These exceptions are hydrogen, helium, lithium, beryllium. These atoms don't need to fulfill the octet rule.
by davidryan3f
Sun Oct 07, 2018 10:28 pm
Forum: Empirical & Molecular Formulas
Topic: When to double moles
Replies: 13
Views: 245

Re: When to double moles

You can round up or down if it is within .1 of the nearest whole number.
by davidryan3f
Sun Oct 07, 2018 10:24 pm
Forum: Empirical & Molecular Formulas
Topic: Converting Units
Replies: 5
Views: 109

Re: Converting Units

Convert the units beforehand so that the math will be valid. For example in an m1v1=m2v2 problem, the volumes must be in the same units.
by davidryan3f
Sun Oct 07, 2018 10:11 pm
Forum: SI Units, Unit Conversions
Topic: What is the notation for molar mass?
Replies: 15
Views: 621

Re: What is the notation for molar mass?

I am pretty sure that it is just an uppercase M (g/mol).

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